Serious crime in the District of Columbia increased 11 percent in the first seven months of this year over the same period last year, police announced yesterday.

Major crimes recorded by police-- homicide, rape, robbery, aggravated assault, burglary, larceny and auto theft -- totaled 37,249 for the first seven months of this year, compared to 33,739 for the same period last year.

Robberies showed the sharpest jump -- 27 percent -- according to figures released by the police department yesterday. But more detailed statistics released by the robbery squad earlier this week showed that within the general category of robbery, armed robberies soared 40 percent and holdups of banks and other financial institutions nearly doubled.

In releasing the crime statistics yesterday, D.C. Police Chief Maurice T. Turner said he is concerned about the increase, adding, "It is my goal to make every area in our city safe."

Though crime is still increasing, Turner said he has been encouraged by what appears to be a slowdown in the increase. Reported crime for the month of July, for example,increased 2 percent over July of last year.

"The increase in crime is showing a downward trend, and I fully expect this trend to continue," Turner said.

Turner said that the department's campaign against illicit drug traffic is continuing. Since Aug. 21, he said, the crackdown has netted 112 arrests and the confiscation of three guns, $3,707 in cash, and various kinds of drug paraphernalia.

According to statistics for the first seven months of this year, the number of reported robberies jumped27 percent over the same period last year from 4,297 to 5,453. Homicides increased 18 percent from 101 to 119 and reported burglaries rose 14 percent from 8,391 to 9,525.

Aggravated assault reports jumped 15 percent from 1,741 to 1,997. Reported auto thefts increased 12 percent from 1,872 to 2,082 and reported larcenies increased 5 percent from 17,096 to 17,850.

The only category with a decrease was rape, down 9 percent from 243 reported cases to 223.